For the light receiving members for use in electrophotography and the like, the public attention has been focused on such light receiving members that have a photoconductive layer formed of an amorphous material containing silicon atoms as the main constituent atoms and hydrogen atoms (hereinafter referred to as "A-Si:H") as disclosed in Unexamined Japanese Patent Publications Nos. Sho. 54 (1979) - 86341 and Sho. 56 (1981) - 83746 since said photoconductive layer has a high Vickers hardness in addition to having an excellent matching property in the photosensitive region in comparison with that in other kinds of light receiving member and it is not harmful to living things as well as man upon the use.
Further, in recent years, a laser printer using the electrophotographic process in which a semiconductor laser having a wavelength of 770 to 800 nm is used as the light source has been tried to make the device practically usable. Its is known that when there is used a light receiving member having a photoconductive layer formed of a silicon containing amorphous material, especially an A-Si material containing a hydrogen atom (H) and/or a halogen atom (X) [hereinafter referred to as "A-Si(H,X)"] in such laser printer, it becomes necessary to show a desired matching property with the semiconductor laser and to bring about a quick photoresponce because of its high photosensitivity in all the wavelength regions of light and especially because of its superior photosensitivity in the long wavelength region of light in comparision with that of the known light receiving member having a selenium light receiving layer.
Further, for the light receiving member as above mentioned, there has been proposed to dispose between the substrate and the photoconductive layer a high resistance intermediate layer formed of a non-monocrystalline material containing silicon atoms as the main constituent atoms and at least one kind atoms selected from oxygen atoms, carbon atoms and nitrogen atoms or/and a charge injection inhibition layer formed of a non-monocrystalline material containing hydrogen atoms and/or halogen atoms in addition to silicon atoms, and a conductivity controlling element of Group III or Group V of the Periodic Table (hereinafter referred to as "Group III element" and "Group V element" respectively) respectively aiming at inhibiting electrons from being injected into the photoconductive layer from the side of the substrate at the time when the light receiving member is engaged in electrification process and permitting the photocarriers, which will be generated in the photoconductive layer and move toward the substrate side at the time when received irradiation of electromagnetic waves, to pass through the substrate side from the photoconductive layer.
There has been also proposed to dispose a layer functioning to absorb light in the long wavelength region (hereinafter referred to as "IR absorption layer") between the substrate and the photoconductive layer in order to eliminate problems often occurring in the case of conducting image exposure using the semiconductor laser as the light source for the above mentioned light receiving member that the light in the long wavelength region which could not be absorbed by the photoconductive layer reflects on the surface of the substrate to cause the occurrence of interference phenomena.
As such IR absorption layer, there has been proposed such that is formed of an amorphous material containing at least one kind atom selected from silicon atom (Si), germanium atom (Ge) and tin atom (Sn).
Now, FIG. 2 is a schematic cross-sectional view illustrating the typical layer composition of the known light receiving member, in which are shown substrate 101, photoconductive layer 102 and high resistance intermediate layer, charge injection inhibition layer or IR absorption layer 103.
For the electroconductive substrate for use in the known light receiving member having a photoconductive layer formed of an A-Si:H material or an A-Si(H,X), there have been used metals such as Al, Ni, Cr, Mo, Au, Nb, Ta, V, Ti, Pt, Pt, etc. or alloys of two or more of these metals such as stainless steel. Among these metals and alloys, metallic materials, aluminum metal or alloys of which principal constituent is aluminum are most preferably used in the viewpoints of their lightness and treatment easiness and also in the economical viewpoint.
This light receiving members are generally prepared by forming on a substrate each of the foregoing IR absorption layer, charge injection inhibition layer, high resistance intermediate layer and photoconductive layer by means of vacuum evaporation, thermal induced chemical vapor deposition, plasma chemical vapor deposition and reactive sputtering.
However, in the case of forming such layers on a substrate of which principal constituent is aluminum (hereinafter referred to as "aluminum substrate") using such film forming process, it is generally recognized that there are several problems as hereunder mentioned.
That is, because the softening point of aluminum is in the range from 150.degree. C. to 200.degree. C., when the aluminum substrate is heated to about 250.degree. C. and maintained at that temperature, a strain is apt to form on the aluminum substrate during the film forming operation.
Further, because there is a difference of about one digit number between the thermal expansion coefficient of aluminum and that of the high resistance intermediate layer, charge injection inhibition layer or IR absorption layer to be formed thereon, cracks are apt to cause in such layer that sometimes results in making the layer peeled off from the substrate.
In order to eliminate the above problems, there has been proposed a method that the temperature of the layer to be formed on the aluminum substrate is gradually elevated to a desired temperature while maintaining that substrate at a relatively low temperature.
However, such method is accompanied with problems that a layer such as an A-Si:H layer to be formed becomes such that is insufficient in its photosensitivity, the characteristics are varied and the yield is decreased.
Against this background, various devices using a light receiving member have been greatly diversified. There is an increased demand for providing a desirable light receiving member having the required layers being disposed on an aluminum substrate which is free from the problems due to the insufficient bondability between the substrate and the layer to be formed thereon and other problems as above mentioned on the known light receiving member, which has a desirable suitability for use in various devices and which also has a wealth of many practically applicable characteristics capable of satisfying various demands required for such various devices.